While the D3 typically loses 20-25% linear resolution upon stepping down from f/5.6 to f/16, the D7000 may lose 40-45%. And the D3200 possibly a good bit more, when an adequate lens is used.

Yes, because D3 is already "blurred" due to it's large pixels. It doesn't have enough resolution. Get a 1mp camera, resolution will be a joke at every aperture, but you won't practically lose anything when stopping down to F/16.

Exactly what did you want to prove with that ad absurdum argument? It is of course valid, but completely irrelevant for the subject, which is the effects of stepping down with the D800. Maybe that's not interesting to you, but it's highly relevant for many D800/800E shooters, in particular those on a budget.